請問這句It was a great mistake my ever letting you into the Throne Room中的my是否要改為i,my letting是什麼意思?謝謝?

It was a great mistake my ever letting you into the Throne Room.
> "my"不能改為"I"或"me", 因為"letting"是動名詞(gerund), 所以在其前面的名詞或代名詞一定要是所有格(possessive case).
> my letting you into = 我(的)讓你進入
> "my ever letting you into the Throne Room" 是 delayed subject
全句可以寫成: My ever letting you into the Throne Room was a great mistake.

it is 形容詞/名詞 + that S + V = It is 形容詞/名詞 + 動名詞片語 
It was a great mistake that I ever let you into the Throne Room.
= It was a great mistake my ever letting you into the Throne Room.